Physics and Astronomy, Ames Laboratory
Journal or Book Title
We report anisotropic thermal expansion of the parent, AEFe2As2 (AE = Ba, Sr, and Ca), compounds. Above the structural/antiferromagnetic phase transition anisotropy of the thermal expansion coefficients is observed, with the coefficient along the a-axis being significantly smaller than the coefficient for the c-axis. The high temperature (200 K ≤ T ≤ 300 K) coefficients themselves have similar values for the compounds studied. The sharp anomalies associated with the structural/antiferromagnetic phase transitions are clearly seen in the thermal expansion measurements. For all three pure compounds, the ‘average’ a-value increases and the c-lattice parameter decreases on warming through the transition, with the smallest change in the lattice parameters observed for SrFe2As2. The data are in general agreement with the literature data from X-ray and neutron diffraction experiments.
This work is published by permission of the US Department of Energy under Contract No. DE-AC02-07CH11358. The US Government retains for itself, and others acting on its behalf, a paid-up, non-exclusive, and irrevocable worldwide licence in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the government.
Bud’ko, Sergey L.; Ni, Ni; and Canfield, Paul C., "Anisotropic thermal expansion of AEFe(2)As(2) (AE = Ba, Sr, Ca) single crystals" (2010). Physics and Astronomy Publications. 684.